I have a T420 I've been using for years. Upgraded to 16GB of RAM, SSD, swapped the dual core i5 for a 4 core/8 thread i7 (yes, the CPU is in a socket!), and swapped the 1600x900 crappy display for a newer 1080p panel that looks much better. I absolutely love this laptop and am not looking forward to the day when it's too old for the modern web.